The brochure “Rubbermaid, Fast Track Garage System” shows an example of a system. The system comprises a suspension bar consisting of a web and a pair of arc-shaped flanges that extend away from the web. A plastic rail cover is slipped onto the horizontally mounted suspension bar. Metal or plastic fastening devices having different hook arrangements can be attached to the suspension bar at any desired position by hooking the top portion of the fastening device onto the upper flange of the suspension bar, on top of the plastic rail cover, and then vigorously forcing the bottom portion of the fastening device past the upper flange of the suspension bar. Not only is a considerable force required to mount and dismount the hook arrangements, they also require a special type of suspension bar with out-turned flanges.